4-1BB信号拮抗肿瘤细胞培养上清诱导的树突状细胞凋亡

为研究4-1BB信号拮抗肿瘤细胞培养上清诱导的树突状细胞(DC)凋亡的作用,采用rmGM-CSF联合rmIL-4诱导小鼠骨髓细胞分化为未成熟树突状细胞(imDC),分别经rmTNF-α、4-1BB激发型单克隆抗体(2A)或TNF-α联合2A激发DC成熟。未成熟或成熟DC分别与不同浓度的肿瘤培养上清混合培养。流式细胞仪测定DC表面CD80、CD86的表达,3H-TdR掺入法测定DC激发T细胞活化增殖能力;JAM法测定未成熟或成熟DC与肿瘤上清混合培养后DNA片断形成率。结果显示:经2A或TNF-α刺激后,DC激发T细胞活化的能力显著提高;5%、10%、20%、50%小鼠肿瘤细胞株A20或B16培养上清与未成熟DC共育24h后,DNA片断形成率分别为16%、29%、41%、51%和20%、27%、37%、58%,且该效应具有时间依赖性;DC经2A或TNF-α激发48h后,不同浓度肿瘤培养上清诱导DNA片断形成率显著降低。因此,肿瘤细胞可以通过分泌可溶性因子诱导未成熟DC凋亡;4-1BBmAb能促进DC的发育成熟,并能有效地抑制肿瘤细胞培养上清诱导的DC凋亡。     

4-1BB信号对小鼠树突状细胞表面TLR4表达的调节

目的 探讨4-1BB（CD137）激发型单克隆抗体2A对小鼠骨髓来源的树突状细胞（DC）表面TLR4表达的调节.方法 用不同剂量2A、LPS以及2A与LPS联合,或用LPS预刺激后再加入2A,以流式细胞术检测这些处理因素作用下DC表面TLR4表达情况.结果 LPS可下调DC TLR4的表达,下调作用可维持24 h,而2A可使DC TLR4的表达上调,上调作用可维持12 h,并可拮抗LPS对TLR4的下调作用.用LPS预处理DC后再加入2A,也可拮抗LPS的下调作用.结论 4-1BB信号可以上调DC表面TLR4的表达.     

小鼠髓系树突状细胞4-1BB及4-1BBL表达调节

探讨小鼠髓系树突状细胞(bone marrow-derived dendritic cells,BMDC)共刺激分子4-1BB及其配体4-1BBL表达的变化。将促DC成熟活化因子CD40L-CHO、TNF-α、LPS和IFN-γ,免疫负性调节因子IL-10以及各成熟活化因子与IL-10联合加入BMDC中,观察BMDC上4-1BB及4-1BBL表达的变化。结果显示,加入成熟活化因子的各组BMDC上4-1BB及4-1BBL表达与对照组相比有显著上调(P<0.05)。而IL-10组与对照组相比两者的表达显著下调(P<0.05),且各成熟活化因子与IL-10联合应用与单用IL-10组相比,BMDC上4-1BB和4-1BBL表达上调,有显著性差异(P<0.05)。提示成熟活化因子不仅能上调BMDC上4-1BB和4-1BBL的表达并且能有效拮抗mIL-10对BMDC上4-1BB和4-1BBL表达的下调作用。     

4-1BBL的分子特性及4-1BB／4-1BBL信号传导在肿瘤免疫治疗的应用

4-1BB/4-1BBL是一组重要的共刺激分子，起初对于4-1BB/4-1BBL研究主要集中于4-1BB作为T细胞表面分子的共刺激作用。最近的证据显示，4-1BBL不只表现一个共刺激分子配基的作用，在本综述中，我们讨论了4-1BBL作为共刺激分子配基的作用：如对CD8^ T细胞的优先增殖和刺激作用，并进一步地讨论了4-1BB/4-1BBL所介导的双信号传导机制，在肿瘤细胞表面表达4—1BBL所引发的免疫机制做一回顾，探讨其用于肿瘤免疫治疗的价值。     

4-1BBL的分子特性及4-1BB/4-1BBL信号传导在肿瘤免疫治疗的应用

4 1BB/ 4 1BBL是一组重要的共刺激分子 ,起初对于 4 1BB/ 4 1BBL研究主要集中于 4 1BB作为T细胞表面分子的共刺激作用。最近的证据显示 ,4 1BBL不只表现一个共刺激分子配基的作用 ,在本综述中 ,我们讨论了 4 1BBL作为共刺激分子配基的作用 :如对CD8+ T细胞的优先增殖和刺激作用 ,并进一步地讨论了 4 - 1BB/ 4 1BBL所介导的双信号传导机制 ,在肿瘤细胞表面表达 4 - 1BBL所引发的免疫机制做一回顾 ,探讨其用于肿瘤免疫治疗的价值。     

树突状细胞疫苗在肿瘤免疫治疗中的作用

树突状细胞是机体内专职的抗原提成细胞,能激活初始型T细胞,因此在免疫反应中具有独特的作用.近年来DC在肿瘤的免疫治疗中的作用受到重视,其发展迅速.本文就这方面的研究进行综述,包括DC与肿瘤发生发展的关系、DC在肿瘤治疗中的具体应用方式、DC疫苗的临床应用研究进展,并重点讲述了以DC为中心的基因治疗方面的进展.     

4-1BB／4-1BBL在T细胞免疫应答及疾病发生中的作用

共刺激分子4-1BB和4-1BB配体（4-1BBL）属于肿瘤坏死因子／肿瘤坏死因子受体（TNF／TN—FR）超家族的重要成员,分别表达在活化的T细胞及树突状细胞（DC）上。4-1BB与4-1BBL相互作用产生的共刺激信号能够促进T细胞增殖、分化以及细胞因子的产生。4-1BB／4—1BBL信号途径在自身免疫性疾病、肿瘤、病毒感染等疾病的发生、发展过程中起着重要的免疫调节作用。干预调节4-1BB／4-1BBL信号途径有望为疾病的免疫治疗提供新的思路。     

共刺激分子:4-1BB和4-1BB配体的研究进展

4 1BB和 4 1BB配体 (4 1BBL)属于肿瘤坏死因子 肿瘤坏死因子受体 (TNF TNFR)超家属成员。近年研究发现 ,4 1BB和 4 1BBL相互作用产生的共刺激信号在机体免疫应答 ,如肿瘤免疫、移植免疫等中起重要作用。因此 ,调节 4 1BB 4 1BBL信号有望成为临床治疗恶性肿瘤 (特别是低免疫原性肿瘤 )和器官移植等所致的免疫功能紊乱的有效手段之一。     

树突状细胞的免疫治疗进展

树突状细胞(DC)是体内专职的抗原提呈细胞,具有摄取、处理和呈递抗原至T细胞的功能,这过程需要MHC分子参与,结合于MHC上的抗原多肽由不同的T细胞亚群所识别。将肿瘤相关抗原(TAA)致敏DC后,回输或接种至荷瘤宿主能显著地诱导机体产生保护性免疫反应。许多TAA在分子水平上的确认以及对DC抗原提呈作用的深入研究,使以DC为基础的肿瘤免疫治疗具有发展前景。     

共刺激分子：4—1BB和4—1BB配体的研究进展

4-1BB和4-1BB配体(4-1BBL)属于肿瘤坏死因子，月中瘤坏死因子受体(TNF/TNFR)超家属成员。近年研究发现，4-1BB和4-1BBL相互作用产生的共刺激信号在机体免疫应答，如肿瘤免疫、移植免疫等中起重要作用。因此，调节4-1BB/4-1BBL信号有望成为临床治疗恶性肿瘤(特别是低免疫原性肿瘤)和器官移植等所致的免疫功能紊乱的有效手段之一。     

Lipopolysaccharide preferentially induces 4-1BB ligand expression on human monocyte-derived dendritic cells

Dendritic cells (DCs) represent a promising tool for immunotherapy. A key feature in their action is to provide co-stimulatory signals for full activation of T cells. In view of recent studies demonstrating the critical role of 4-1BB co-stimulation in T cell response, it is of importance to optimize 4-1BB ligand (4-1BBL) expression on human monocyte-derived DCs (MDDCs), the DC source of many clinical studies. In this study, two types of MDDCs, generated in granulocyte-macrophage colony-stimulating factor and interleukin-4 (GM-CSF/IL-4-DCs) or in interferon-β and IL-3 (IFN-β/IL-3-DCs), were analyzed for 4-1BBL expression in response to several known DC activators. Immature MDDCs expressed 4-1BBLs at very low levels. Lipopolysaccharide (LPS) was the only activator that preferentially triggered 4-1BBL expression on either MDDCs, but 4-1BBL-positive cells were significantly more frequently observed on LPS-activated GM-CSF/IL-4-DCs (30.2±2.6% versus 14.3±1.2%). Combinations of multiple activating signals did not bring about enhanced 4-1BBL stimulatory capacity. In addition, plasmid DNA transfection and necrotic cell pulsing of GM-CSF/IL-4-DCs for antigen loading also resulted in 4-1BBL up-regulation. However, in all circumstances, the induced 4-1BBL levels were low in comparison with CD80 co-stimulatory molecule. Finally, by demonstrating LPS-matured GM-CSF/IL-4-DCs from sorted 4-1BBL^high population augmented T cell expansion and survival, we propose that efforts are required to increase 4-1BBL levels on MDDCs achieved by current activation schemes.     

Expression and function of 4-1BB and 4-1BB ligand on murine dendritic cells

4-1BB (CDw137) and its ligand (4-1BBL) have been implicated in cellular immune responses. To further characterize the expression and function of 4-1BBL, we newly generated an anti-mouse 4-1BBL mAb (TKS-1), which can inhibit the interaction of 4-1BBL with 4-1BB. Flow cytometric analyses using TKS-1 and an anti-mouse 4-1BB mAb indicated that 4-1BB was inducible on both CD4(+) and CD8(+) splenic T cells by stimulation with immobilized anti-CD3 mAb, but 4-1BBL was not expressed on resting or activated T cells. 4-1BBL expression was inducible on splenic B cells by stimulation with anti-IgM antibody plus anti-CD40 mAb, on peritoneal macrophages by stimulation with lipopolysaccharide (LPS) and on splenic dendritic cells (DC) by stimulation with anti-CD40 mAb or LPS. Interestingly, splenic DC expressed 4-1BB constitutively, which was down-regulated by anti-CD40 stimulation. Co-culture of splenic DC with 4-1BBL-transfected cells or 4-1BBL-expressing tumor cell lines led to cytokine (IL-6 and IL-12) production and co-stimulatory molecule up-regulation by splenic DC, indicating that 4-1BBL can directly activate DC. Moreover, IL-12 production by anti-CD40-stimulated DC was partially inhibited by TKS-1. These results suggest that 4-1BB expressed on DC may be involved in DC activation through DC--tumor interaction and DC--DC interaction.     

The role of dendritic cells in neuroblastoma: Implications for immunotherapy

Neuroblastoma is a solid tumor, which is originated from some neural tissues. The immune system including the innate and adaptive immune system fights against this tumor. Dendritic cells (DCs) play an important role in this way by recognizing tumor antigens and activating specific types of T cells. These cells are derived from monocytes that are induced by inflammatory factors secreted by different cells in the tumor microenvironment (TME). There are different types of DCs, including monocyte-derived DCs (moDC), plasmacytoid DCs (pDC), conventional DCs type 1 and 2 (cDC1 and cDC2), and Langerhans cells. DCs connect the innate and the adaptive part of the immune system and have an important role in anti-tumor immunity. There are some vaccines that involve specific types of DCs, which can be used to prevent neuroblastoma. Also, we can use the combination of inflammatory factors and DCs as a substitute for chemotherapy.     

4-1BB signaling beyond T cells

Originally discovered as a T cell-activating molecule, 4-1BB (CD137) is now also recognized as an activator of non-T cells, thus imparting a new dimension to its potential in vivo effects. 4-1BB expression is seen on a variety of non-T cells including activated dendritic cells (DCs), monocytes, neutrophils, B cells and natural killer (NK) cells, and promotes their individual effector functions. The T cell- and non-T cell-activating ability of 4-1BB may be the basis of its powerful anti-cancer, anti-autoimmune and anti-viral effects. Here we discuss the consequence and importance of 4-1BB signaling in non-T cells. We consider its effects on immune regulation, and the distinct and/or overlapping pathways involved in these responses, as well as possible therapeutic applications.     

阿霉素联合致敏树突状细胞对荷宫颈癌小鼠的治疗作用

 目的：探讨阿霉素(adriamycin,ADM)联合冻融抗原致敏的树突状细胞(dendritic cells,DCs)对荷宫颈癌小鼠的免疫治疗作用。方法：建立小鼠皮下移植瘤模型;应用反复冻融法处理小鼠宫颈癌U14细胞,并致敏小鼠骨髓来源的DCs,制备DCs疫苗;流式细胞术鉴定DCs成熟表型;荷瘤小鼠分为对照组（PBS组）、DCs疫苗组、ADM组和ADM联合DCs疫苗组,进行3个周期的治疗。观察肿瘤大小,第21 d取血,ELISA法检测小鼠血清IL-2、IL-12和IFN-γ含量;处死动物,称肿瘤重量。结果：肿瘤冻融抗原致敏DCs后,可高表达白细胞分化抗原CD11c、CD80和CD86;经3个周期的治疗后,ADM联合DCs疫苗组平均瘤重及平均瘤体积均小于ADM组、DCs疫苗组和对照组(P＜0.05),联合治疗组抑瘤率大于其它3组(P＜0.05),且血清IL-2、IL-12和IFN-γ水平明显升高 (P＜0.05)。结论：ADM联合肿瘤抗原致敏的DCs疫苗可增强动物的抗肿瘤免疫应答,能有效抑制荷宫颈癌小鼠肿瘤的生长。     

CD4+ CD25+调节性T细胞对树突状细胞的杀伤作用

目的 探讨CD4^＋CD25^＋调节性T细胞是否对树突状细胞发挥免疫调节作用及其可能的机制。方法 用MACS（magnetic cell sorting）从BALB／c小鼠静息T细胞分离纯化CD4^＋CD25^＋T细胞，体外细胞增殖实验观察其对CD4^＋CD25^＋T细胞的免疫抑制作用；GM-CSF／IL-4培养自体小鼠骨髓来源DC，FACS（fluorescence-activated cell sorting）鉴定其表面分子特性；以CD3／CD28单克隆抗体活化CD4^＋CD25^＋调节性T细胞，FACS体外杀伤实验研究其对自体DC的调节作用，并观察穿孔素抑制剂EGTA对上述作用的影响。结果 用MACS法成功分离出CD4^＋CD25^＋T细胞，纯度可达98％，特异性表达而Faxp3基因，能明显抑制CD4^＋CD25^＋T细胞的体外增殖；骨髓来源的DC表达CDllc、MHCⅡ及少量协同刺激分子CD80、CD86；FACS体外杀伤实验证实以CD3／CD28抗体体外活化的CD4^＋CD25^＋调节性T细胞对自体DC有显著杀伤作用（P〈0．05），穿孔素抑制剂EGTA能部分抑制该杀伤效应（P〈0．05）。结论 CD4^＋CD25^＋调节性T细胞可通过杀伤作用对自体DC发挥免疫调节作用，穿孔素／颗粒酶杀伤途径可能参与其中。     

Immunotherapy of malignant melanoma with tumor lysate-pulsed autologous monocyte-derived dendritic cells

Purpose

Dendritic cell (DC) vaccination for melanoma was introduced because melanoma carries distinct tumor-associated antigens. The purpose of this study was to investigate the efficacy and safety of DC vaccination for melanoma in Korea.

Materials and Methods

Five patients with stage IV and one with stage II were enrolled. Autologous monocyte-derived DCs (MoDCs) were cultured and pulsed with tumor-lysate, keyhole limpet hemocyanin, and cytokine cocktail for mature antigen-loaded DC. DC vaccination was repeated four times at 2-week intervals and 2-4×10⁷ DC were injected each time.

Results

Reduced tumor volume was observed by PET-CT in three patients after DC vaccination. Delayed type hypersensitivity responses against tumor antigen were induced in five patients. Tumor antigen-specific IFN-γ-producing peripheral blood mononuclear cells were detected with enzyme-linked immunosorbent spot in two patients. However, the overall clinical outcome showed disease progression in all patients.

Conclusion

In this study, DC vaccination using tumor antigen-loaded, mature MoDCs led to tumor regression in individual melanoma patients. Further standardization of DC vaccination protocol is required to determine which parameters lead to better anti-tumor responses and clinical outcomes.     

Loading of dendritic cells for immunotherapy

Dendritic cell therapy has been optimized a lot aiming to induce a strong and broad immune response in terms of the recognized epitopes by both CD8⁺ and CD4⁺ T cells and the use of the patients' complete unique set of HLA molecules. We here give an overview of our approach for antigen loading and maturation of dendritic cells and describe the consequences to evaluate the immune response after treatment as well as the Brussels experience in clinical trials.